Many chording keyboards, in particular, the one described in FR85/11532 (Guyot-Sionnest), are already known.
From U.S. Pat. No. 4,344,069, US 2003/063775, U.S. Pat. No. 5,535,421, WO 97/23816 and “HP48 G Series User's Manual” the following are already known, respectively:                a device making it possible to generate characters by successively pressing two keys, where the character is produced upon raising the second key,        a device making it possible to evaluate and calculate three-dimensional distances in applications such as virtual keyboards,        guiding device for a keyboard user where the guiding consists of displaying the production means activated by the user and the character produced by the means activated,        a computer method for user identification according to their behavioral profile, and        a user manual for a calculator which assigns several producible characters by a single key by means of one or more selection keys (α key).        
The drawback of these solutions resides in the fact that they are not suited for being used both by a novice who is taking time to learn the device's operation and an expert who seeks performance from the device. In fact, because of its complexity and burden, the first step of discovering and learning chording keyboards always rebuffed the user who most often abandoned it. No initial guidance or even adaptation as a function of the user's dexterity and hesitations is offered. None of these solutions proposes unique equipment making it possible to unite the production of objects via a simultaneous and successive key activation mode.